Vehicle lamps, such as headlamps, are commonly mounted to a vehicle frame by threaded adjustment shafts. By threading one or more of the adjustment shafts, the orientation of the headlamp with respect to the vehicle may be changed. The headlamp is then aimed by properly screwing the adjustment shafts in or out until the lamp is pointed correctly. It is also common practice to use a ball and socket type coupling to join the headlamp, or equivalently a headlamp support frame, to an end of the adjustment shaft. In some designs, the adjustment shafts extend from the vehicle to the headlamp, and in others the design is reversed, so the shafts extend from the headlamp frame to the vehicle. In some designs there are three adjustment shafts, in some there are only two. Typically, one vertical and one horizontal adjustment shaft are used with one pivot shaft. If three ball and socket adjustment shafts are used, the head lamp may be clipped on or off for easy installation.
In manufacturing an automobile, the headlamp needs to be properly aligned before the final sale. Alignment takes time, and therefore costs the consumer money. A headlamp may be aligned by shining the lamp on a screen marked with a proper aligned region. By adjusting the lamp mounts, the projected beam may be properly aligned. Manual alignment is too time consuming to be acceptable. Computer driven feed back systems may be used to replace manual labor methods, but even computer driven adjusters take time along the assembly process. Proper initial manufacture should be able to reduce or eliminate the need for time consuming adjustment. There is then a need for a substantially prealigned headlamp for use in automobile manufacture.
Vehicle lamps may fail or may be damaged and therefore need to be replaced. Replacement may be done by the vehicle owner without access to a proper vehicle lamp alignment facility. The result is then a poorly aligned vehicle lamp. Replacement may also be performed at a service center where labor is expensive, so a quick alignment procedure is needed. There is then a general need for a mechanism to assist proper alignment of a vehicle lamp.
Headlamps are being made with a smaller vertical profile to help enhance vehicle aerodynamics. The reduced profile headlamps have too small a vertical extension to be easily aimed like older lenses, where three aiming pads were formed on the lens face to which an aiming device could be attached. The aiming pads could be used by a computer driven robot in a factory setting, or by a human observing a bubble gauge device in a service center. For the low profile lamps, there may be too little vertical separation to adequately adjust the lamps. As a result there is a need for an alternative means for adjusting headlamp aiming in service centers and elsewhere, and in particular without the need for special alignment equipment.
Examples of the prior art are shown in U.S. Pat. Nos. 3,949,215; 4,188,655; 4,293,897; and 4,318,162.
U.S. Pat. No. 3,949,215 issued Apr. 6, 1976 to George Whitney for Lamp Assembly threaded shafts with ball and socket couplings for use in headlamp alignment hardware. Three threaded shafts extend from a support plate to couple in ball sockets formed on the lamp housing.
U.S. Pat. No. 4,188,655 issued Feb. 12, 1980 to Thomas G. Tallon for Vehicle Headlamp and Mounting Assembly shows threaded shaft and ball and socket couplings used in headlamp alignment hardware. Two threaded shafts are shown extending from the lamp housing to threaded couplings in the vehicle, while a single ball pivot forms the third support.
U.S. Pat. No. 4,293,897 issued Oct. 6, 1981 to Alain Deverrewaere for Motor Vehicle Headlamp shows several ball and socket type couplings used in headlamp alignment hardware. Screws extend from a casing to ball sockets formed in the lamp housing.
U.S. Pat. No. 4,318,162 issued Mar. 2, 1982 to Jiri G. Sip for Snap in Coupling Assembly for A Vehicle Headlamp shows ball and socket couplings used in headlamp aiming hardware. One shaft is shown extending from the vehicle to a ball socket formed on the lamp housing, while a second shaft is shown extending from the lamp housing to a ball socket formed on the vehicle.
The National Highway Traffic Safety Administration (NHTSA) has published additional requirements for on vehicle headlamp aiming features (FMVSS 108 S7.7.5.2). The requirements are for readable markings related to proper headlamp adjustment. In particular, a zero marking is required, along with regular gradations of no more than 0.19 degrees each from 1.2 degrees azimuthal above and below horizontal. The aiming accuracy is to be 0.1 degrees or better. A similar horizontal aiming requirement is also established. A zero mark is required along with regular gradations of not more than 0.38 degrees left and right of forward for a range of at least 0.76 degrees left and right with an accuracy of 0.1 degrees or better. The horizontal indicator shall be recalibratable over a range of 2.5 degrees right or left of forward. These standards were published in the Federal Registry, Vol. 54, No. 88, Tuesday May 9, 1989, p. 20079-20080.